The present invention relates to a steel laminate gasket with sealing means readily responsive to outer force applied thereto.
Recently, an engine of an automobile has been developed to become light in weight and provide high power. Since a steel laminate gasket is mechanically strong and can seal around cylinder holes with high combustion pressure, the steel laminate gasket has been used widely.
One of a conventional steel laminate gasket is shown in FIG. 8, wherein a gasket 20 comprises an upper plate 21, a lower plate 24, a middle plate 22, and a middle plate 23 with a bead 23a around a cylinder hole Hc to be sealed. The lower plate 24 is provided with a curved portion 24a around the cylinder hole Hc, and a flange 24b situated above the upper plate 21.
In some cases, the middle plate 23 is deleted, and instead, a bead is formed in the lower plate 24 to surround the cylinder hole Hc.
The conventional steel laminate gaskets as stated above seal around the cylinder hole properly. However, in case a steel laminate gasket is required to be thin and to seal around a hole at a relatively lower tightening pressure, the above gasket 20 as well as the gasket with the bead at the lower plate are not suitable. The gasket 20 is not suitable because the gasket 20 is relatively thick. Also, the gasket with the bead at the lower plate is not suitable, because a relatively high tightening pressure is required for sealing the gasket since the curved portion is formed adjacent to the bead.
Accordingly, one object of the invention is to provide a steel laminate gasket which is thin and can seal properly with a relatively low tightening pressure.
Another object of the invention is to provide a steel laminate gasket as stated above, which can relatively easily slide relative to a member that the gasket abuts when a stress is applied to the gasket.
A further object of the invention is to provide a steel laminate gasket as stated above, wherein a relatively wide sealing area is provided around a hole to be sealed.
A still further object of the invention is to provide a steel laminate gasket as stated above, wherein the gasket can be easily and economically manufactured.
Further objects and advantages of the invention will be apparent from the following description of the invention.